Systems, methods, and apparatus for a homopolar generator charger with integral rechargeable battery

ABSTRACT

Systems, methods, and apparatus for providing a homopolar generator charger with an integral rechargeable battery. A method is provided for converting rotational kinetic energy to electrical energy for charging one or more battery cells. The method can include rotating, by a shaft, a rotor in a magnetic flux field to generate current, wherein the rotor comprises an electrically conductive portion having an inner diameter conductive connection surface and an outer diameter conductive connection surface, and wherein a voltage potential is induced between the inner and outer diameter connection surfaces upon rotation in the magnetic flux field. The method can also include selectively coupling the generated current from the rotating rotor to terminals of the one or more battery cells.

FIELD OF THE INVENTION

This invention generally relates to battery charging, and in particular,to a homopolar electrical generator charger with an integralrechargeable battery.

BACKGROUND OF THE INVENTION

A homopolar generator is a unique electrical generator, sometimesreferred to as a Faraday disk after Michael Faraday, who developed thebasic device in 1831. The homopolar generator can convert rotationalenergy into direct current by rotating an electrically conductive discin a plane perpendicular to a magnetic field. Faraday's law ofelectromagnetic induction and/or Lorentz's force law can be utilized toexplain the operation of the homopolar generator. The radial movement ofthe electrons in the disc in the presence of the magnetic field producesa charge separation between the center of the disc and its rim, and ifthe circuit is completed between the disk center and rim, an electriccurrent will be produced when the disc is rotated.

Versions of the homopolar generator have been used to supply currents upto 2 million amperes, but practical use has been limited due primarilyto the low voltage output and high I²R losses that can arise fromimperfect electrical brush connections to connect external circuits.

Conventional battery chargers and alternators are typically designed forcharging several battery cells in series, with charging currents limitedby the additive internal resistance of each cell in the series. Chargingcells of a battery in series tends to require extended charging periods.For example, a typical multi-cell 10 ampere-hour battery requiresroughly 15 hours to reach full charge from a fully discharged conditionwith a 1 ampere charger.

Electric cars and other electric vehicles utilize battery packs havingmultiple rechargeable cells that are connected in series to provideadequate voltages for driving electric motors. One of the barriers forcommercial success of the all electric car, however, is the longassociated battery charging times. Part of the issue that can contributeto the long charging time is the internal series resistance that limitsthe amount of charging current that can flow through the battery. Somedesigners and manufactures have proposed systems to swap out the entirebattery each time it is discharged to address the charging time issue.

BRIEF SUMMARY OF THE INVENTION

Some or all of the above needs may be addressed by certain embodimentsof the invention. Certain embodiments of the invention may includesystems, methods, and apparatus for a homopolar generator with integralrechargeable battery.

According to an example embodiment of the invention, an apparatus isprovided. The apparatus includes an elongated shaft defining alongitudinal axis of rotation; at least one rechargeable batterycomprising at least one cell having a positive and negative terminal,the at least one battery mounted substantially coaxially with respect tothe shaft; one or more magnets for providing a magnetic flux field; arotor comprising an electrically conductive portion having an innerdiameter conductive connection surface and an outer diameter conductiveconnection surface, the rotor mounted coaxially in communication withthe shaft, wherein the rotor is operable to rotate in the magnetic fluxfield; at least one positive output electrode operable for selectiveelectrical communication with at least one of the battery cell positiveterminal, the rotor inner diameter conductive connection surface, or therotor outer diameter conductive connection surface, wherein the at leastone positive output electrode is stationary relative to the rotatingshaft; at least one negative output electrode operable for selectiveelectrical communication with at least one of the battery cell negativeterminal, the rotor outer diameter conductive connection surface, or therotor outer diameter conductive connection surface, wherein the at leastone negative output electrode is stationary relative to the rotatingshaft; and a connection system comprising one or more brushes forelectrically connecting one or more of the rotor conductive connectionsurfaces or the battery terminals with one or more of the outputelectrodes. According to an example embodiment, the rechargeable batteryis operable to rotate with the rotor.

According to another example embodiment, a system is provided. Thesystem includes a motor; an elongated shaft defining a longitudinal axisof rotation; at least one rechargeable battery comprising at least onecell having a positive and negative terminal, the at least one batterymounted substantially coaxially with respect to the shaft; one or moremagnets for providing a magnetic flux field; a rotor comprising anelectrically conductive portion having an inner diameter conductiveconnection surface and an outer diameter conductive connection surface,the rotor mounted coaxially in communication with the shaft, wherein therotor is operable to rotate in the magnetic flux field; at least onepositive output electrode operable for selective electricalcommunication with at least one of the battery cell positive terminal,the rotor inner diameter conductive connection surface, or the rotorouter diameter conductive connection surface, wherein the at least onepositive output electrode is stationary relative to the rotating shaft;at least one negative output electrode operable for selective electricalcommunication with at least one of the battery cell negative terminal,the rotor outer diameter conductive connection surface, or the rotorouter diameter conductive connection surface, wherein the at least onenegative output electrode is stationary relative to the rotating shaft;and a connection system comprising one or more brushes for electricallyconnecting one or more of the rotor conductive connection surfaces orthe battery terminals with one or more of the output electrodes.

According to another example embodiment, a method is provided forconverting rotational kinetic energy to electrical energy for chargingone or more battery cells. The method includes rotating, by a shaft, arotor in a magnetic flux field to generate current, wherein the rotorincludes an electrically conductive portion having an inner diameterconductive connection surface and an outer diameter conductiveconnection surface, and wherein a voltage potential is induced betweenthe inner and outer diameter connection surfaces upon rotation in themagnetic flux field; and selectively coupling the generated current fromthe rotating rotor to terminals of the one or more battery cells,wherein the terminals comprise a positive terminal and a negativeterminal, and wherein the positive terminal and a negative terminal areelectrically connected to respective inner and outer, or outer and innerdiameter connection surfaces, wherein the at least one battery cell ismounted substantially coaxially with respect to the shaft.

Other embodiments, features, and aspects of the invention are describedin detail herein and are considered a part of the claimed inventions.Other embodiments, features, and aspects can be understood withreference to the following detailed description, accompanying drawings,and claims.

BRIEF DESCRIPTION OF THE FIGURES

Reference will now be made to the accompanying tables and drawings,which are not necessarily drawn to scale, and wherein:

FIG. 1 is a diagram of an illustrative homopolar generator rotor,according to an example embodiment of the invention.

FIG. 2 is a side-view depiction of an illustrative homopolar generatorcharger with an integral battery, according to an example embodiment ofthe invention.

FIG. 3 is a side-view depiction of another illustrative homopolargenerator charger with an integral battery, according to an exampleembodiment of the invention.

FIG. 4 is a diagram a rechargeable battery for use with the homopolargenerator charger, according to an example embodiment of the invention.

FIG. 5 is a circuit diagram of a homopolar generator charger with arechargeable battery and a stationary switching controller, according toan example embodiment of the invention.

FIG. 6 is a circuit diagram of a homopolar generator charger with arotating rechargeable battery and switching controller, according to anexample embodiment of the invention.

FIG. 7 is a flow diagram of an example method according to an exampleembodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

Embodiments of the invention will be described more fully hereinafterwith reference to the accompanying drawings, in which embodiments of theinvention are shown. This invention may, however, be embodied in manydifferent forms and should not be construed as limited to theembodiments set forth herein; rather, these embodiments are provided sothat this disclosure will be thorough and complete, and will fullyconvey the scope of the invention to those skilled in the art.

Example embodiments can include a homopolar generator having one or morerechargeable battery cells. In example embodiments, electricalconnections may be selectively switched to connect the cells to thehomopolar rotor center and rim during rotation to charge and/ordischarge the cells simultaneously. In an example embodiment, the one ormore rechargeable battery cells can be selectively switched, whenappropriate, to an external circuit for providing DC current output.According to example embodiments, the one or more cells can beselectively connected in parallel during charging or discharging. In canexample embodiment, two or more cells can be connected in series toprovide increased DC voltages for output to an external circuit.According to example embodiments, the rechargeable battery cells mayrotate with the conductive rotor and a switching controller to eliminateone or more pairs of brush connections and/or to provide low resistanceswitchable connections from the generator rotor to the battery cells.

Various parts may be used and arranged for achieving efficient batterycharging, according to example embodiments of the invention, and willnow be described with reference to the accompanying figures.

FIG. 1 depicts an illustrative homopolar generator 100 with a rotor 102,according to an example embodiment. According to an example embodiment,the rotor 102 includes at least a conductive surface. In other exampleembodiments, the rotor 102 may be a solid conductive disk. In accordancewith example embodiments, additional rotors may be utilized in thehomopolar generator charger. In example embodiments, the conductiveportion of the rotor may include metals with high conductivity,preferably copper. However, other metals including silver, gold,aluminum, nickel, etc may be utilized.

According to an example embodiment, the rotor 102 may be in mechanicaland electrical contact with a shaft 104, which may provide linkage forrotation, and may provide a rotor inner diameter connection surface. Inexample embodiments, the rotor may include an outer diameter connectionsurface 108. In accordance with example embodiments, a voltage potentialmay be induced between the inner diameter (in electrical connection withthe shaft 104, for example) and the outer diameter connection surface108. The voltage polarity is dependent on the direction of rotation andthe orientation of the magnetic field with respect to the rotorrotation. The voltage magnitude is a function of the square of the rotorradius, the rotation speed, and the magnetic field strength. Accordingto an example embodiment, the rotor radius 110 may be set to provide acertain voltage output for a rotation speed and magnetic field strength.According to other example embodiments, the shaft 104 may beelectrically isolated from the rotor 102, and an inner diameterconnection surface may be provided for completing a circuit for whichcurrent may flow.

FIG. 2 is a side-view depiction of an illustrative homopolar generatorwith an integral battery 200, according to an example embodiment. Inthis example embodiment, a magnet assembly, having a north pole 201 anda south pole 202, may provide a magnetic flux 206 for interaction withthe conductive rotor 212. In an example embodiment, the 201, 202 may bejoined by an optional return path 208 to assist in aiding return flux210 and to reduce the magnetic reluctance associated with the magneticflux path. According to example embodiments, the magnets, as describedherein, may have a sufficient diameter to produce a magnetic field witha diameter that is larger than the diameter of the rotor so that theentire rotor is exposed to the magnetic field. According to exampleembodiments, multiple permanent magnets may be arranged, for example, inan adjacent north-south-north-south configuration, or with interveningcomponents between the magnets.

According to one example embodiment, the magnet assembly may bemechanically separated from the shaft 204 and mounted separately so thatthe shaft 204 and other attached components may rotate independentlyfrom the magnet assembly. In another example embodiment, the magnetassembly may be mechanically coupled with the shaft 204, and the magnetassembly may rotate with the shaft 204. Certain advantages/disadvantagesin terms of weight, inertia, mounting complexity, etc. for example, mayprovide reasoning for rotating the magnets, or for providing stationarymagnets. A surprising result that is not readily apparent from Faraday'slaws is that it does not matter whether the magnetic field rotates ornot. In one embodiment, rotating magnets may add to the mass of thegenerator and may require more inertial energy to spin the rotor whilenot otherwise changing the outcome in any useful way. However, accordingto another example embodiment, it may be advantageous to have the extramass of the spinning magnet for storage of rotational energy.

According to example embodiments, the homopolar generator 200 includes arechargeable battery 216. In one example embodiment, the rechargeablebattery 216 can be fixed to the shaft 204 and/or the conductive rotor212, and may rotate with these parts. In another example embodiment, theshaft 204 and/or the conductive rotor 212 can be configured to rotateindependent of the rechargeable battery 216.

According to example embodiments, the shaft 218 may provide an innerdiameter connection surface for providing a slideable electricalconnection with a first electrode brush 218. In an example embodiment,the conductive rotor 212 can include an outer diameter connectionsurface (as in 110 of FIG. 1) for providing a slideable electricalconnection with a second electrode brush 220. In accordance with exampleembodiments, if the rechargeable battery 216 may include two or moreouter diameter connection surfaces for slideable electrical connectionswith battery electrode brushes 222. According to example embodiments,two brushes may be utilized to provide circuit connection access to thepositive and negative terminal of the rechargeable battery. In exampleembodiments, multiple rechargeable battery cells 216 may be utilized inthe homopolar generator charger 200, each with similar connections forexternal circuits, as previously described.

According to example embodiments, and as will be further explained withreference to FIGS. 3, 5, and 6, a switching controller may be used toselectively connect, switch, and/or disconnect circuits associated withthe homopolar generator charger 200.

Many other configurations for the rechargeable batteries 216, theconductive rotor 212, the magnets 201, 202, and the associatedconnecting components may be envisioned without departing from the scopeof the inventions. For example, it may be advantageous to electricallyisolate the shaft 204 from the rest of the mechanism. In such an exampleembodiment, an optional insulator 214 may be utilized to electricallyseparate the inner diameter of the conductive rotor 212 from the shaft204. In this example embodiment, the first electrode brushes 218 may beconfigured to contact with an inner diameter of the conductive rotor212, at a slideable connection surface on the conductive rotor at adiameter outside the region of the optional insulator 214.

FIG. 3 depicts yet another example embodiment of a homopolar generator300 having a battery 308 and a switching controller 320 that areoperable for rotating with the conductive rotor 306. In this exampleembodiment, the magnet 301 may be configured to be stationary, or it maybe configured to rotate with the shaft 304, the conductive rotor 306,the switching controller 310 and the battery 308. In this exampleembodiment, one magnet 301 is depicted having opposing poles 302 in aplane perpendicular to the conductive rotor 306 so that the magneticlines of flux pass substantially perpendicularly through the conductiverotor. Other example embodiments may include more than one magnet 301(such as in FIG. 1).

The following illustrative example may help provide part of thereasoning for having a direct electrical connection configuration, asshown in FIG. 3. A mid-sized, typical homopolar generator may bedesigned to produce an output of 3 volts at a current of 1000 amperes (3KW). A slip ring pair with brushes for connecting with the rotor mayhave a combined series resistance of 0.01 ohm. The I²R loss associatedwith brush connections is 1000²×0.01=10 KW, which is three times greaterthan the output of the generator. Therefore, the typical homopolargenerator almost always ends up being extremely inefficient. Accordingto example embodiments, FIG. 3 depicts direct electrical connections320, 322 from the conducting rotor to the switching controller 310, anddirect electrical connections 316, 318 to/from the battery 308.According to example embodiment, direct electrical connection mayprovide low resistance connections among the rotor 306, controller 320,and battery 308 so that I²R losses may be minimized.

In the example embodiment of FIG. 3, first electrode brushes 312 andsecond electrode brushes 314 may be utilized for electrically completingconnections from the switching controller 310 to external circuits. Forexample, the first electrode brush 312 may connect to a ground ornegative portion of an external (and non-rotating) circuit, and secondelectrode brush 314 may connect to a positive portion of the externalcircuit, or vice versa.

According to example embodiments of the invention, the directconnections 316, 318, 320, 322 may provide low resistance connectionsfor charging the battery 308. In certain example embodiments, thebattery 308 may include multiple cells, each with direct connection tothe controller 310. According to an example embodiment, the controller310 may provide connections for hooking each of the battery cells inseries for outputting power at higher voltages, and perhaps lowercurrents, so that less power is lost at the electrode brushes 312, 314,which provide slideable electrical connections, for example, tonon-rotating external circuits. Additional details for this embodimentwill be further described in reference to FIG. 6.

FIG. 4 depicts an example rechargeable battery 400, having an anode 402a cathode 404, a first electrode 406, and a second electrode 408.According to an example embodiment, the rechargeable battery 400 mayinclude a separator 410 between the anode 402 and the cathode 404.According to an example embodiment, the anode and cathode placement maybe switched to provide opposite polarity for the battery outputelectrodes. According to example embodiments, the polarity of thebattery, which may depend on the orientation or placement of the anodeand cathode, may be matched with the polarity output from the homopolargenerator rotor, which depends on the direction of rotation of therotor, and the orientation of the magnetic field. According to oneexample embodiment, the rechargeable battery 400 may rotate with theshaft, the rotor, and switching controller. In such an embodiment, thebattery electrodes 406, 408 may be directly connected to connectionsassociated with a switching controller (as in FIG. 3). In anotherexample embodiment, the battery may be configured to be non-rotating, orto rotate independently from the rotor. In such embodiments, an optionalbearing 412 may be utilized so that the shaft may rotate independent ofthe battery 400.

FIG. 5 depicts an example circuit diagram of a homopolar generatorcharger 500 with a non-rotating switching controller 506. In thisexample embodiment, a motor 530 may be utilized to turn the rotor 502.(The magnetic field is not shown in this diagram, but it is assumedpresent with the correct orientation). According to an exampleembodiment, a battery 504 (or optionally, two or more cells as indicatedby the dashed lines) may be selectively connected to the rotor 502 or tooutput connections 516, 518, 520, 522 via battery brushes 512, 514,and/or the rotor outer brush 510 and shaft brush 508. In an exampleembodiment, the switching controller 506 may connect the rotor positiveportion to an output 524, which may be configured for outputindependent, or in conjunction with the battery output. According toexample embodiments, the switching controller may be utilized forconnecting two or more battery cells 504 in parallel for charging, andmay be operable to isolated cell positive and negative outputs forserial connection of the batteries for higher voltage output. Inaccordance with example embodiments, the switching controller 506 mayelectrically disconnect one or more connections with the rotor 502 whenthe rotor speed falls below a given threshold value, or when chargingcurrent associated with the batteries has reached a predetermined value.

FIG. 6 depicts an example circuit diagram of a homopolar generatorcharger 600 with an integrated switching controller 605 and battery orcells 604 that are operable to rotate with the rotor 602. The examplecircuit diagram of FIG. 6 may correspond to a configuration similar tothat as shown in FIG. 3. According to an example embodiment, a motor 620may be used to rotate the rotor 602, the switching controller 605, andthe battery or cells 604. In other example embodiments, the rotor 602,switching controller 605, and the battery or cells 604 may be rotatedvia components associated with a regenerative braking system. Accordingto an example embodiment, the rotor 602, switching controller 605, andthe battery or cells 604 rotate in concert and at least some of theelectrical connections between these devices may be hard wired.According to an example embodiment, two output brushes 610 may providean electrical connection from the components that are operable forrotating, to a non-rotating positive output electrode 612 and anon-rotating negative electrode 614. According to example embodiments,the reduction of brushes may provide power efficiency advantages, aspreviously discussed. In accordance with certain example embodiments,the output brushes 610 may be placed in close proximity to (or on) therotor shaft of the homopolar generator charger 600 to reduce frictionand to minimize wear.

According to example embodiments, the switching controller 605 mayinclude one or more switching networks 607 that may be utilized toselective close and open circuits among the rotor 602, the battery orcells 604, and the output brushes 610. In example embodiments, one ormore diodes may be utilized to limit current flow to one direction inany of the circuits. According to example embodiments, relays or otherswitching devices having high current capacity and low resistance whenengaged may be utilized for switching elements in the switching network607. In example embodiments, the controller 605 may additionally includea microprocessor 606, a rotation sensor 608, a voltage detector 618,and/or a battery 609. In another example embodiment, a receiver and/ortransmitter may be included in the controller 605 for wirelesscommunication with an external controller.

According to an example embodiment, the microprocessor 606 may beutilized for receiving information, and for directing the switchingnetwork 607 based upon input such as rotation speed, rotation direction,etc. According to example embodiments, the voltage detector circuit 618may be used for monitoring the voltage across the battery, one or morecells, and/or the rotor. In example embodiments, the microprocessor 606may also receive signals from the voltage detector circuit 618 and maydirect the switching network 607 accordingly. According to exampleembodiments, the switching network 607 may connect the battery or cells604 with the rotor 602 for charging when a voltage across the rotor 602has reached or exceeded a predetermined value, or when a certainrotational speed has been reached. According to an example embodiment,power may be supplied externally by the homopolar generator charger 600via output brushes 610 by connecting one or more of the rotor 602,battery or cells 604 to the output. According to an example embodiment,the rotor 602 may be switched out of circuit and the battery or cells604 may be connected to the output for supplying power to externaldevices via the output brushes 610. According to example embodiments,two or more cells may be connected in series via the switching network607 to provide power output at an increased voltage.

An example method 700 for converting rotational kinetic energy toelectrical energy for charging one or more battery cells will now beexplained with reference to FIG. 7. In block 702, and according to anexample embodiment, the method 700 includes rotating, by a shaft, arotor in a magnetic flux field to generate current, wherein the rotorcomprises an electrically conductive portion having an inner diameterconductive connection surface and an outer diameter conductiveconnection surface, and wherein a voltage potential is induced betweenthe inner and outer diameter connection surfaces upon rotation in themagnetic flux field. In block 704, the method 700 includes selectivelycoupling the generated current from the rotating rotor to terminals ofthe one or more battery cells, wherein the terminals comprise a positiveterminal and a negative terminal, and wherein the positive terminal anda negative terminal are electrically connected to respective inner andouter, or outer and inner diameter connection surfaces, wherein the atleast one battery cell is mounted substantially coaxially with respectto the shaft. The method 700 ends after block 704.

According to example embodiments, brushes may be utilized for makingelectrical connections of surfaces on the rotor, controller, and/orbattery. According to example embodiments, such surfaces may includeslip rings that may provide conductive surfaces for which the brushesmay make electrical contact with portions of the rotor, controller,and/or battery. In example embodiments, the brushes may include metalfibers, carbon compounds, or conductive liquids, such a liquid metal.

According to example embodiments, certain technical effects can beprovided, such as creating certain systems, methods, and apparatus thatprovide efficient utilization of energy conversion. Example embodimentsof the invention can provide the further technical effects of providingsystems, methods, and apparatus for providing high currents for chargingbattery cells.

In example embodiments of the invention, the homopolar generator charger200, 300, 500, 600 may include any number of hardware and/or softwareapplications that are executed to facilitate any of the operations.

In example embodiments, one or more I/O interfaces may facilitatecommunication between the homopolar generator charger 200, 300, 500,600, and one or more input/output devices. The one or more I/Ointerfaces may be utilized to receive or collect data and/or userinstructions from a wide variety of input devices. Received data may beprocessed by one or more computer processors as desired in variousembodiments of the invention and/or stored in one or more memorydevices.

One or more network interfaces may facilitate connection of thehomopolar generator charger inputs 200, 300, 500, 600 and outputs to oneor more suitable networks and/or connections; for example, theconnections that facilitate communication with any number of sensorsassociated with the system. The one or more network interfaces mayfurther facilitate connection to one or more suitable networks; forexample, a local area network, a wide area network, the Internet, acellular network, a radio frequency network, a Bluetooth™ (Owned byTelefonaktiebolaget LM Ericsson) enabled network, a Wi-Fi™ (owned byWi-Fi Alliance) enabled network, a satellite-based network any wirednetwork, any wireless network, etc., for communication with externaldevices and/or systems.

As desired, embodiments of the invention may include the homopolargenerator charger 200, 300, 500, 600, with more or less of thecomponents illustrated in FIGS. 1-6.

According to additional example embodiments, the rotor may include acomposite conductive structure. For example, the rotor may be made withmaterials including, but not limited to fiberglass, sintered metals,alloys, graphite composites, etc. According to example embodiments, therotor conductive surface or disk may be evaporated or deposited onto abase material. According to example embodiments, the rotor may include acopper outer casing. According to example embodiments, the homopolargenerator charger may include an outer casing that may be made ofvarious non-conducting materials with the required structuralproperties. In example embodiments the homopolar generator may includeelectrodes or electrical connection regions or surfaces that are madefrom of nickel oxyhydroxide and/or a hydrogen absorbing alloy. Accordingto example embodiments, two or more rotors can be stacked to providedifferent configurations, redundancy, and/or increased power outputcapacity.

According to example embodiments, the homopolar generator charger mayprovide pulsed current output. For example, a connecting circuit may becompleted and opened in succession to provide a current path between therotor inner and outer conductive regions and other components. In anexample embodiment, during the period when the connecting circuit isopen, a charge differential may build on the rotor until a balance ofcharge is met. Closing the circuit may allow the electrons to flow,similar to a capacitor, until charge is depleted.

According to example embodiments, frictional losses due to rotation ofthe rotor, battery, and other associated rotating components may bereduced by dimpling any surface where there is no brush or contact. Thisincludes unused areas of the shaft and areas that have clearance for airto pass between, and can be applied to the facing surfaces of the magnetarray and magnets themselves. According to example embodiments, drag maybe reduced via the dimpling by creating a boundary layer of turbulentair at exposed surfaces. In an example embodiment, dimpling may also beutilized to enhance heat dissipation.

According to an example embodiment, the homopolar generator charger'srotor may comprise a solid copper disk and a battery as previouslydescribed. Experiments have shown that an 18 inch by ¼ A inch solidcopper rotor is capable of sustaining 1500 amps in a field of 13000gauss. In an example embodiment, copper may be applied to the outersurfaces of the rotor via electroplating. In an example embodiment, therotor may be made from a solid copper disk or from an alloy. In anexample embodiment, a solid shaft made from a similar alloy, andconfigured to pass through the disk center, may facilitate theconduction of electricity and maintain the structural integrity of theunit.

In example embodiments, the rotor and shaft can be supported by variousmeans. According to an example embodiment, a housing or structure maysupport the rotor assembly in position and may to allow the rotor torotate on a common axis. According to an example embodiment, ends of therotor may be supported on roller bearings. In an example embodiment,pressurized gas, oil, or magnetic suspension may be utilized to reducemechanical resistance. According to example embodiments, ceramics andother non-conducting components may be utilized to eliminate currentflow in unwanted areas.

In accordance with example embodiments, current may be supplied toexternal component, or between components associated with the homopolargenerator via brushes. In example embodiments, solid copper, graphite,sintered, liquid metal, or other brushes may be mounted in standardbrass holders on each side of the rotor's shaft and on the periphery ofthe rotor conductor or disk.

According to example embodiments, the generated current and/or voltageoutput from the homopolar generator rotor may be dependent on themagnitude of the magnetic field, the square of the conductor's radiusimmersed in the magnetic field of a given magnitude, and the angularvelocity of the conductive portion of the rotor. Other factors affectingoutput include composition and size of the conductor or rotor,mechanical resistance, magnetic coupling with exterior objects, brushmaterials, etc. Eddy currents allowed to flow in a portion of the diskor conductor outside the field can reduce the efficiency.

According to another example embodiment, portions of the rotor mayinclude embedded wound coils, each connected in a manner to produce avoltage and current output. According to an example embodiment, astator, comprising multiple stationary magnets arranged in alternatingnorth-south-north-south ring configuration, may be mounted around thecenter of a larger magnet. In an example embodiment, a drive motor maybe integrated with the rotor. In an example embodiment, a wire-woundgenerator may be utilized as a motor. In accordance with exampleembodiments, regenerative systems, which may include a generator/motormay be used in conjunction with the homopolar generator charger.

According to this example embodiment, an inner generator/motor may beutilized in conjunction with the rotor of the homopolar generator. Forexample, an inner generator/motor may comprise a hub-type of wire-woundmotor. In accordance with an example embodiment, when the rotor isdecelerating or coasting, the rotor may act as a flywheel. In an exampleembodiment, kinetic energy from the rotor assembly may providemechanical leverage when the motor is switched to generating mode, suchas in a regenerative system. Accordingly, the rotor in the regenerativemode may have certain mechanical advantage due to its proximity to thecenter of the shaft. However it may have the classic back torque or backelectromotive force associated with standard generators. The back torqueor back electromotive force may be minimal if designed for low voltageof 3 volts or less.

According to example embodiments, outer (non-rotating) magnetssurrounding the inner (rotating) magnets may be utilized for producingthe high currents that are typically associated with a homopolargenerator with a solid conductor disc rotor. According to exampleembodiments, rectification may be utilized for the inner magnet portion,and the outer portion associated with the stationary part may producedirect current.

Example embodiments may utilize a circumferentially segmented rotor madeof at least two conductors isolated from each other at theirperipheries. Other example embodiments may include a rotor having aconductor shaped in the form of a spiral.

In accordance with an example embodiment, the homopolar generatorcharger may include a composite copper disk mounted inside amagnetically closed metal housing. In an example embodiment, magnets maybe attached to the inside of the housing. For example, the housing mayinclude two half pieces, having parabolic-shape, or other suitableshape. In example embodiments, bearings may be mounted in the center ofeach half, allowing the magnetic flux from ends of the single or stackedmagnets to couple back through the housing. This arrangement may reduceexternal fields and magnetic coupling of exterior ferrous objects.According to an example embodiment, the housing may be made of soft orcast iron. Example embodiments of the housings may be heat treated forfixing dipole alignment (or randomization) of the material. According toan example embodiment, nickel may be included in the housing material toreduce hysteresis. In other example embodiments, laminated structuresmay be employed reduce induced eddy currents. In an example embodiment,a brush system (solid or liquid) may be mounted and isolatedelectrically at the center between the halves of the housing structure.In an example embodiment, outer diameter surface of the brush assemblymay be constructed from the same materials as the housing halves toallow the magnetic flux a point of return.

According to an example embodiment, the rotor may include integratedrings of individual rechargeable batteries or cells separated byinsulators. In one example embodiment, the innermost battery or cell maybe placed in a ring adjacent to the shaft. In an example embodiment, theinnermost battery or cell may be surrounded radially by a second batteryor cell, and so-forth to a desired diameter. According to an exampleembodiment, as the circumference is increased, the radial thickness ofeach cell or battery may be modified to keep each battery or cell ringat approximately the same internal resistance.

According to another example embodiment, a straight shaft design may beutilized in high speed applications ranging from approximately 10,000 toapproximately 100,000 revolutions per minute. In this embodiment, ashaft may be made of neodymium-iron-boron being solid in constructionbut with appropriate thickness to carry high currents withoutoverheating. Any number of raised surfaces can be machined into theouter surface of the rotor shaft. According to example embodiment, theraised machined surfaces may be located over the center of any opposingmagnetic fields. In an example embodiment, the surface of the shaft maybe electroplated with conductive metal to reduce oxidation and providepoints of brush contact for current output. According to an exampleembodiment, the shaft may be capped with bearing supports of magneticmaterial or ferrous ends for oil, air, and gas or magnetically floated.In accordance with an example embodiment, the shaft, when rotated athigh speed, may maintain a negative polarity on the shaft center withcharge separation occurring at or near the surface of the shaft.Accordingly, charge separation may occur at the point of the centerlinewhere the magnetic flux is closest to zero. According to exampleembodiment, brush slots may be filled with a liquid metal and cappedunder slight pressure, and lugs may be milled into these areas forcurrent extraction. In accordance with an example embodiment, the outerhousing may be made from cast iron to close the unused poles and forcethe internal magnetic flux lines compress and concentrate in the areawhere outer raised areas of the shaft may intersect the compressedfields at 90 degrees. In an example embodiment, this type of generatorcan be used in high temperature applications, such as in turbine exhaustsystems, and may recover energy form systems that have exhaust as abyproduct of operation. Any enclosed tube in which a liquid, gas, orvapor flows from a high potential to a lower potential is a candidatefor this type of generator.

According to an example embodiment, a rotor assembly made of printedcircuit material may be utilized to provide a voltage potential orcurrent source. In an example embodiment, the printed circuit rotor maybe mounted to shaft. In an example embodiment, the printed circuit rotormay be mounted adjacent to another rotor. Example embodiments mayinclude a multilayer printed circuit rotor. Example embodiments mayinclude an integrated switching controller with or adjacent to theprinted circuit rotor. The printed circuit rotor may provide alightweight design and may allow for complex conductive patterns on therotor.

Example embodiments may include a conducting disk composed of aconductor or materials that conduct electricity and mounted on a shaftor axle so that it can be rotated within the fields of one or morepermanent magnets. According to example embodiments, the magnets have asufficient diameter to produce a field that is larger than the diameterof the disk or rotor. In an example embodiment, the disk may include acomposite copper rotor or other conductor in which current and voltageis known to flow when rotated in a magnetic field. The rotor may includean inner and outer diameter conducting rings or surfaces, as describepreviously. The area between the inner and outer diameter conductingrings or surfaces may include layers of capacitor components in a radialorientation. In one example embodiment, the negative terminal of thecapacitor component may be connected at the center, and positiveterminal may be configured for electrical connection at the outerradius. According to example embodiments, the capacitor may include twoconductors separated by a dielectric or non-conductive region orinsulator. The conductors thus hold equal and opposite charges on theirinner and outer surfaces, and the dielectric develops an electric field.According to example embodiments, the capacitor parts may be arranged ina cylindrical form.

According to example embodiment, rotor systems in a cylindrical shapemay have a shaft made from NdFeB material or is cast in the requiredshape. In example embodiments, beryllium or copper conductors can befitted to the NdFeB shaft to allow for current extraction directly fromthe ends.

Example embodiments, may include both the shaft and rotor combination toinclude both the north and south pole, with a conductor of copper orother material fit to the center of the magnetic rotor. Such anembodiment, may draw current through the magnet and shaft, being theconductor in combination. This example embodiment may result in aconfiguration similar to a standard rotor system, but it may includecomposite NdFeB for current conduction. Example embodiments may includeelectroplating the assembly with highly conductive materials prior tomagnetization to both protect the NdFeB from the elements and provide aconductive path for the flow of current, all in one assembly. Theassembly may then be magnetized through its thickness one side beingnorth and the other being south. The conducting ring being mounted inits centerline may provide the highest concentration of field strengths,as the highest fields are on the surface and interiors of the magnets.In an example embodiment, the rotor section is magnetized. In thisconfiguration, the north side may rotate in the same direction as thesouth.

In accordance with example embodiments, the rotor system may be mountedon or in many enclosure configurations, and may have either a closedmagnetic flux circuit or open magnetic circuit. According to one exampleembodiment, a rotor may be supported by non-magnetic pedestals, but mayutilize permanent- or electro-magnets. In one example, magnets may beapproximately six inches in diameter, one half inch thick, and mayinclude a one and three-eighths inch hole in the center for the shaft topass through. In an example embodiment, six magnets may be used.According to an example embodiment, the first magnets on each side of adivided housing may be bolted to the housing. The next two magnets maybe magnetically coupled north to south or vice versa, three on eachside. This arrangement may be utilized to increase and guide themagnetic field. In an example embodiment, two halves of a housing may beassembled in a way that may subsequently receive additional components,including the rotor, shaft, rechargeable battery, switching controller,etc.

In accordance with example embodiments presented herein, it should beunderstood that the housings and materials mentioned are not onlysubject to electromagnetic or permanent magnet fields, but also fieldsthat are created by the flow of current within the system. All of thefactors that govern permanent sources of fields may also apply to fieldscreated by current flow. In example embodiments, shielding may beutilized to prevent or guide certain forces. For example, somematerials, such as non-ferrous brushes and copper conductors, may becomeattracted to each other through the magnetic force created by currentflow, and may need to be shielded to prevent unwanted forces.

In accordance with example embodiments, the rotating portion of thehomopolar generator charger may include a stack of disk shaped rotorsbetween stationary or affixed magnets, so that the magnets rotate withthe shaft. In this example configuration, the rotor disk, batter disk,magnet disk(s), and any switching control circuitry may be mounted on acommon shaft.

Example embodiments may include many options for the type ofrechargeable battery or cell to be used in a system, and may bedependent on many factors, such as use or type of application,environment or generator configuration, battery resistance, chargeabsorption over time, temperature, and issues such as electrolyteseparation due to centrifugal forces.

Nickel metal hydride (NmH) batteries may be utilized as rechargeablebatteries, according to an example embodiment. Such batteries may have alow internal resistance, and may have high durability. Lithium-basedcells (for example, lithium-ion, lithium-polymer, etc.) may be utilizedas rechargeable batteries, according to another example embodiment.According to one example embodiment, a dual battery bank system may beused, for example, to provide power from one bank while another bank ischarging. According to example embodiment, a switching system, such asthe ones previously describe, may be used for selective routing ofinternal conductors.

According to an example embodiment, an internal or external bank ofbatteries may be charged at low voltage and high current using thehomopolar generator charger. According to this example embodiment,batteries may be charged as individual cells in parallel. According toan example embodiment, the bank can include individual cells. Forexample, NiM cells may have nominal associated voltages of approximately1.2 to 1.5 volt. Li cells may have nominal associated voltages in therange of approximately 2.8 to 3.3 volts. Bank size or number of cellsmay be determined by the amount of energy needed by the load for a giventime. A generator size may also be determined based on the size of thebattery bank. For example, 180 1.2 volt batteries may requireapproximately 300 amps to recover from a 90% discharge. An examplegenerator capable of providing the 300 amps and at a voltage of 1.5volts, according to embodiments, could conceivably recharge the hank in15 minutes. If the depth of discharge is less, then the time required toreach 100% charge may be reduced. For comparison purposes, a bank ofthis size can take from 2 to 20 hours to recharge by conventional means,particularly if the batteries are charged in series.

According to example embodiments, after reaching full (or near fullcharge), the battery bank may be switched to a series configuration toprovide an increased voltage output for powering devices. In an examplewhen a discharge limit is reached, the bank may be switched back toparallel and current may be directed to charge the bank.

According to an example embodiment, and as previously discussed, abattery or cell bank may be rotated with the rotor. In an exampleembodiment, a disk shaped battery may include a center hole being eithera positive or negative pole. In an example embodiment, the battery maybe approximately 8 inches in diameter, approximately 5/16 of an inchthick with approximately a 1 inch diameter hole in the center for theshaft to pass through, or for attachment to the shaft. In an exampleembodiment, the outer shell of the battery may be copper or copper cladto form the rotor. According to an example embodiment, the negativeterminal of the battery may include an electrode composed of a hydrogenabsorbing alloy. The electrode may be in a grid or it may be perforatedto increase its surface area. According to example embodiments, thepositive electrode can include nickel oxyhydroxide. According to anexample embodiment, a disk battery of this size would weighapproximately 2.5 pounds. Each battery may be capable of 800 to 1000watts per kilogram specific power.

According to example embodiments, one or more rotors may be mounted on acommon shaft. Each may be separated by a disk shaped magnet with thepoles on the faces north and south. Such an example configuration mayalso be connected in series to provide higher voltage potentials but atlower amperage capacity. The reverse is also true with lower potentialand higher amperage capacity.

According to example embodiments, the applications for the homopolargenerator charger system may include, but are not limited to wind energyharnessing, automotive electric vehicle industries, geothermal systems,hydropower, tidal and wave energy harnessing, uninterruptible powersupplies, emergency power, etc. For example, instead of large generatorsproducing high speed and high voltage potentials, the generator could bea low speed, high current design that could provide current in line withthe nature of high capacity cells. Advantages may include a reductionweight, operation under light loads or cruising speeds, and highefficiency.

While certain embodiments of the invention have been described inconnection with what is presently considered to be the most practicaland various embodiments, it is to be understood that the invention isnot to be limited to the disclosed embodiments, but on the contrary, isintended to cover various modifications and equivalent arrangementsincluded within the scope of the appended claims. Although specificterms are employed herein, they are used in a generic and descriptivesense only and not for purposes of limitation.

This written description uses examples to disclose certain embodimentsof the invention, including the best mode, and also to enable any personskilled in the art to practice certain embodiments of the invention,including making and using any devices or systems and performing anyincorporated methods. The patentable scope of certain embodiments of theinvention is defined in the claims, and may include other examples thatoccur to those skilled in the art. Such other examples are intended tobe within the scope of the claims if they have structural elements thatdo not differ from the literal language of the claims, or if theyinclude equivalent structural elements with insubstantial differencesfrom the literal language of the claims.

1. An apparatus comprising: an elongated shaft defining a longitudinalaxis of rotation; at least one rechargeable battery comprising at leastone cell having a positive and negative terminal, the at least onebattery mounted substantially coaxially with respect to the shaft; oneor more magnets for providing a magnetic flux field; a rotor comprisingan electrically conductive portion having an inner diameter conductiveconnection surface and an outer diameter conductive connection surface,the rotor mounted coaxially in communication with the shaft, wherein therotor is operable to rotate in the magnetic flux field; at least onepositive output electrode operable for selective electricalcommunication with at least one of the battery cell positive terminal,the rotor inner diameter conductive connection surface, or the rotorouter diameter conductive connection surface, wherein the at least onepositive output electrode is stationary relative to the rotating shaft;at least one negative output electrode operable for selective electricalcommunication with at least one of the battery cell negative terminal,the rotor outer diameter conductive connection surface, or the rotorinner diameter conductive connection surface, wherein the at least onenegative output electrode is stationary relative to the rotating shaft;and a connection system comprising one or more brushes for electricallyconnecting one or more of the rotor conductive connection surfaces orthe battery terminals with one or more of the output electrodes.
 2. Theapparatus of claim 1, wherein the rechargeable battery is operable torotate with the rotor.
 3. The apparatus of claim 1, wherein the rotor isoperable to rotate in a direction substantially perpendicular to adirection associated with the magnetic flux field.
 4. The apparatus ofclaim 1, further comprising a switching controller that is stationaryrelative to the rotating shaft and electrically connected the rotorconnection surfaces and the battery terminals via one or more brushesand further configured for selectively: closing one or more circuitsbetween the rotor connection surfaces and the cell terminals when agenerated voltage across the rotor has exceeded a predefined threshold;opening the one or more circuits between the rotor connection surfacesand cell terminals when the generated voltage across the rotor is belowa predefined threshold; closing one or more circuits between cellterminals and the output electrodes; or closing one or more circuitsbetween rotor connection surfaces and the output electrodes.
 5. Theapparatus of claim 1, further comprising a switching controller operableto rotate with the rotor, wherein the switching controller is configuredfor selectively connecting electrically with one or more of the rotorconnection surfaces or the cell terminals.
 6. The apparatus of claim 5,wherein the switching controller comprises: one or more voltagedetectors for monitoring one or more of rotor voltage or cell voltage;one or more rotation sensors for monitoring rotation of the rotor orcells; and a switching network operable for selectively establishing orbreaking connections between the output electrodes and one or more ofthe rotor connection surfaces or cell terminals, the based at least inpart on the monitored voltages or monitored rotation.
 7. The apparatusof claim 5, wherein the switching network is configured for selectively:closing one or more circuits between the rotor connection surfaces andthe cell terminals when a generated voltage across the rotor hasexceeded a predefined threshold; opening the one or more circuitsbetween the rotor connection surfaces and cell terminals when thegenerated voltage across the rotor is below a predefined threshold;closing one or more circuits between cell terminals and the outputelectrodes; or closing one or more circuits between rotor connectionsurfaces and the output electrodes.
 8. An system comprising: a motor; anelongated shaft defining a longitudinal axis of rotation; at least onerechargeable battery comprising at least one cell having a positive andnegative terminal, the at least one battery mounted substantiallycoaxially with respect to the shaft; one or more magnets for providing amagnetic flux field; a rotor comprising an electrically conductiveportion having an inner diameter conductive connection surface and anouter diameter conductive connection surface, the rotor mountedcoaxially in communication with the shaft, wherein the rotor is operableto rotate in the magnetic flux field; at least one positive outputelectrode operable for selective electrical communication with at leastone of the battery cell positive terminal, the rotor inner diameterconductive connection surface, or the rotor outer diameter conductiveconnection surface, wherein the at least one positive output electrodeis stationary relative to the rotating shaft; at least one negativeoutput electrode operable for selective electrical communication with atleast one of the battery cell negative terminal, the rotor outerdiameter conductive connection surface, or the rotor inner diameterconductive connection surface, wherein the at least one negative outputelectrode is stationary relative to the rotating shaft; and a connectionsystem comprising one or more brushes for electrically connecting one ormore of the rotor conductive connection surfaces or the batteryterminals with one or more of the output electrodes.
 9. The system ofclaim 8, wherein the rechargeable battery is operable to rotate with therotor.
 10. The system of claim 8, wherein the rotor is operable torotate in a direction substantially perpendicular to a directionassociated with the magnetic flux field.
 11. The system of claim 8,further comprising a switching controller that is stationary relative tothe rotating shaft and electrically connected the rotor connectionsurfaces and the battery terminals via one or more brushes and furtherconfigured for selectively: closing one or more circuits between therotor connection surfaces and the cell terminals when a generatedvoltage across the rotor has exceeded a predefined threshold; openingthe one or more circuits between the rotor connection surfaces and cellterminals when the generated voltage across the rotor is below apredefined threshold; closing one or more circuits between cellterminals and the output electrodes; or closing one or more circuitsbetween rotor connection surfaces and the output electrodes.
 12. Thesystem of claim 8, further comprising a switching controller operable torotate with the rotor, wherein the switching controller is configuredfor selectively connecting electrically with one or more of the rotorconnection surfaces or the cell terminals.
 13. The system of claim 12,wherein the switching controller comprises: one or more voltagedetectors for monitoring one or more of rotor voltage or cell voltage;one or more rotation sensors for monitoring rotation of the rotor orcells; and a switching network operable for selectively establishing orbreaking connections between the output electrodes and one or more ofthe rotor connection surfaces or cell terminals, the based at least inpart on the monitored voltages or monitored rotation.
 14. The system ofclaim 12, wherein the switching network is configured for selectively:closing one or more circuits between the rotor connection surfaces andthe cell terminals when a generated voltage across the rotor hasexceeded a predefined threshold; opening the one or more circuitsbetween the rotor connection surfaces and cell terminals when thegenerated voltage across the rotor is below a predefined threshold;closing one or more circuits between cell terminals and the outputelectrodes; or closing one or more circuits between rotor connectionsurfaces and the output electrodes.
 15. A method for convertingrotational kinetic energy to electrical energy for charging one or morebattery cells; the method comprising: rotating, by a shaft, a rotor in amagnetic flux field to generate current, wherein the rotor comprises anelectrically conductive portion having an inner diameter conductiveconnection surface and an outer diameter conductive connection surface,and wherein a voltage potential is induced between the inner and outerdiameter connection surfaces upon rotation in the magnetic flux field;and selectively coupling the generated current from the rotating rotorto terminals of the one or more battery cells, wherein the terminalscomprise a positive terminal and a negative terminal, and wherein thepositive terminal and a negative terminal are electrically connected torespective inner and outer, or outer and inner diameter connectionsurfaces, wherein the at least one battery cell is mounted substantiallycoaxially with respect to the shaft.
 16. The method of claim 15, whereincoupling the generated current to the at least one battery cellcomprises rotating the at least one battery cell with the rotor.
 17. Themethod of claim 15, wherein rotating the rotor in a magnetic field togenerate current comprises rotating the rotor in a directionsubstantially perpendicular to a direction associated with the magneticflux field.
 18. The method of claim 15, further comprising selectively:closing one or more circuits between the rotor connection surfaces andthe terminals of the one or more battery cells when the voltagepotential has exceeded a predefined threshold; opening the one or morecircuits between the rotor connection surfaces and the terminals of theone or more battery cells when the voltage potential is below apredefined threshold; closing one or more circuits between the terminalsof the one or more battery cells and output electrodes; or closing oneor more circuits between the rotor connection surfaces and the outputelectrodes.
 19. The method of claim 15, further comprising: sensing thevoltage potential; sensing a voltage associated with the one or morebattery cells; monitoring rotation of the rotor; and selectivelyestablishing or breaking connections between the output electrodes andone or more of the rotor connection surfaces or the battery cellterminals based at least in part on the monitored voltages or rotation.20. The method of claim 15, further comprising: sensing the voltagepotential across the rotor connection surfaces; sensing a voltageassociated with the one or more battery cells; monitoring rotation speedof the rotor; selectively closing one or more circuits between the rotorconnection surfaces and the cell terminals when the sensed voltagepotential across the rotor has exceeded the sensed voltage associatedwith the one or more battery cells; and selectively opening the one ormore circuits between the rotor connection surfaces and cell terminalswhen the sensed voltage potential across the rotor is less than thesensed voltage associated with the one or more battery cells or when themonitored rotation speed of the rotor is less than a predeterminedvalue.